Bitcoin Core - Whonix chapter Tor Control Protocol in Whonix wiki
/usr/share/doc/onion-grater-merger/examples/40_bitcoind.yml has ADD_ONION so adding DEL_ONION seems to make sense too.
Please report an upstream bug as it probably shouldn’t crash even in that case.
Dunno. Same as if using Tor outside of Whonix. Unspecific to Whonix.
Needs to be investigated as per: